Field of the Invention
The present invention relates to a bicycle sprocket, and in particular, to a method for manufacturing a bicycle cogset that can be modularized to increase the efficiency of manufacture and production and reduce a manufacturing cost.
Description of Related Art
Generally, a rear cogset of a variable-speed bicycle has multiple rear sprockets with different sizes assembled on it, and these sprockets are assembled together on a sleeve, where the sleeve is sleeved on a rear hub, and the rear hub is connected to a rear wheel of the bicycle. Pedaling pedals of the bicycle drives a front chainwheel to rotate, the front chainwheel is connected to the rear cogset by a chain hanging thereon, and the chain can be moved by a derailleur of the bicycle to move between two different sprockets of the rear cogset according to a different road condition, so as to drive the bicycle to move forward.
FIG. 1 and FIG. 2 show a bicycle cogset according to Taiwan utility model patent No. M451318, including a base 60, a plurality of long fixing members 70 and short fixing members 74, a large sprocket 80 with the largest outer diameter, a first sprocket 90, a second sprocket 91, a third sprocket 92, and a fourth sprocket 93. The base 60 has a cylindrical body 61, an outer portion of the body 61 is provided with six supporting arms 62, each of the supporting arms 62 has a first surface 63 and a second surface 64 that are opposite to each other, the second surface 64 is provided with a first step portion 641 and a second step portion 642 that are in a staircase shape, the thickness of the first step portion 641 is greater than that of the second step portion 642, and each of the first step portion 641 and the second step portion 642 is provided with a through hole 65. The first surface 63 of each of the supporting arms 62 is provided with the large sprocket 80, and a mounting hole 81 is disposed to correspond to the through hole 65 of the first step portion 641. The first sprocket 90, the second sprocket 91, the third sprocket 92, and the fourth sprocket 93 are disposed sequentially in a direction of the second surface 64. A plurality of mounting holes 901, 911, 921, and 931 corresponding to the long fixing members 70 is respectively distributed annularly on the first sprocket 90, the second sprocket 91, the third sprocket 92, and the fourth sprocket 93. Each of the long fixing members 70 has a large-diameter portion 71, a long shaft 72, and a short shaft 73, so that the first sprocket 90 is riveted by the long fixing members 70 through the mounting holes 901, the fixing members 70 pass through the mounting holes 911 of the second sprocket 91, the through holes 65 of the first step portions 641, and the mounting holes 81 of the large sprocket 80, and finally rivets the large sprocket 80 to the first surface 63.
Each of the short fixing members 74 has a large-diameter portion 75, a long shaft 76, and a short shaft 77. The third sprocket 92 and the fourth sprocket 93 are riveted and fixed by the short shafts 77 of the short fixing members 74 by passing through the mounting holes 921 of the third sprocket 92, and by the long shafts 76 of the short fixing members 74 by passing through the mounting holes 931 of the fourth sprocket 93 and the through holes 65 of the supporting arms 62. As a result, the first sprocket 90, the second sprocket 91, the third sprocket 92, the fourth sprocket 93, and the large sprocket 80 are passed through and riveted by the plurality of long fixing members 70 and the plurality of short fixing members 74, and are integrated together with the base 60.
In assembly, manual work is required, so that the short shaft 73 of the long fixing members 70 passes through the mounting hole 901 of the first sprocket 90, and the long shaft 72 of the long fixing members 70 passes through the mounting hole 911 of the second sprocket 91 and the through hole 65 of the first step portion 641 and is riveted to the first surface 63; and the short shaft 77 of the short fixing members 74 passes through rocket 92, and the long shaft 76 of each of the short fixing members 74 passes through the mounting hole 931 of the fourth sprocket 93 and the through hole 65 of the supporting arm 62 and riveted to the fourth sprocket 93 and the supporting arm 62. It can be seen that the assembly process is quite time-consuming and troublesome, and the matching precision of the elements is difficult to control, which do not satisfy economical requirements.